Vent question

I'm moving a bathroom sink to a different wall and draining to existing 2" underfloor drain about 6' away. New drain pipe within wall will travel 18" horizontal, 18" vertical to area below floor, another 18" horizontal to connect to existing 2" drain with 1 1/2" vent. Can I use the existing vent? Or, do I have to install a new vent in the wall behind the new sink?

Vent question

Quote:

Originally Posted by TVC15

Why would I need a sanitary tee if I'm going from the sink's trap to the existing waste line that already has a vent?

After the trap. the pipe goes horizontal. It has to hit a vent before dropping down to the drain below the floor. If not, it's considered an "s" trap which will, in most cases, cause problems with siphonage. Then you're house will stink and no one will want to visit!

Vent question

Thanks for the explanation. There is a 2" vent pipe for the toilet a few feet away in the same wall my sink will be located. Can I run a horizontal vent pipe into a tee attached to the toilet vent? I believe the horizontal vent pipe has to be 6-8" above the sink.

Vent question

Vent question

My next issue - or, maybe it's not a problem. I have to run the horizontal vent pipe through two 2 x 4 studs that are part of a weight bearing wall. (It's not the main weight bearing wall.) Any precautions, comments? There is no attic space for connection to the existing vent.

Vent question

Quote:

Originally Posted by TVC15

My next issue - or, maybe it's not a problem. I have to run the horizontal vent pipe through two 2 x 4 studs that are part of a weight bearing wall. (It's not the main weight bearing wall.) Any precautions, comments? There is no attic space for connection to the existing vent.

Vent question

Instead of going across with the 18” trap arm, then down to underfloor area and across to drain; can I run the trap arm 18’ across to the existing toilet vent in the wall? I would use a sanitary tee and create a drain and a vent in the existing toilet vent pipe. Or, do I need a vertical vent line immediately after the trap?

Vent question

Quote:

Originally Posted by TVC15

Instead of going across with the 18” trap arm, then down to underfloor area and across to drain; can I run the trap arm 18’ across to the existing toilet vent in the wall? I would use a sanitary tee and create a drain and a vent in the existing toilet vent pipe. Or, do I need a vertical vent line immediately after the trap?

in my code, you have to vent within 3.5 feet on 1.5" pipe you can also use 180 degrees of turn. you'd be good in my state as long as the vent on the wc is at least 2"